Use lodash isEqual to check if a model is dirty

[benjamincanac]

Proposed changes

This fix uses _.isEqual instead of !== in the dirty getter to compare $attributes and $originalAttributes.

This allows comparaison with json objects.

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist

• I have read the CONTRIBUTING doc
• Lint and unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works.
• I have added necessary documentation (if appropriate)

[thetutlage]

Yes, this makes sense

[thetutlage]

Thanks 😄